thanks for this really important info, that LALR(1) is not suitable for
error reporting. However in SableCC a good error reporting is realized,
although SableCC also is LALR(1). I think this can be realized because
the lookahead token are not calculated at runtimethe but at the same
time the parser is gettiing generated from the grammar.

So I have to possibilities: either I realize the calculation of the
lookahead token like in sablecc or I take an LR(1) parser.

I haven't searched for a LR(1) parser generator yet (I will do this
after this message ;), but do you know a good one?